Safety cut-out



(No Model.)

M THUM SAFETY OUT-OUT.

No. 472,084. Patented Apr. 5, 1892.

I nVe/n'bor .1

Wkwnd Witnesses UNITED STATES PATENT OFFICE.

MANDEVILLE THUM, OF LOUISVILLE, KENTUCKY.

SAFETY CUT-OUT.

SPECIFICATION forming part of Letters Patent No. 472,084, dated April5,1892. Application filed June 5, 1891- Serial No. 395,269. (No model)T0 at whom/it may concern.-

Be it known that 1, MANDEVILLE THUM, a citizen of the United States,residing at Louisville, in the county of Jefferson and State ofKentucky, have invented certain new and useful Improvements in Apparatusfor Insuring and Increasing the Safety of Electric Circuits orConductors, of which the following is a specification.

The object of the improvement is to insure or enhance the safety ofelectric circuits or conductors, especially those which are used forelectric lighting, railway, or power purposes. This I accomplish byguarding them in such manner that a signal is given or that a change inthe circuitsuch as a break, a decrease of its conductive capacity, orthe substitution for the whole or a part of it of other conductingdevices--is automatically effected upon the occurrence of an accidentsuch as the breaking of a conductor of the guarded circuit or thecrossing of it by another conductoror upon the occurrence of otherconditions which render such change desirable, but which may not comewithin the term accident.

To this end my invention consists in the combination, with a maincircuit or circuit to be guarded, of a safety device comprising a branchcircuit connected with said guarded circuit and an electro mechanicaldevice of suitable character in a branch circuit and adapted to operateto change the guarded circuit upon a change of the currentin the latter.

My invention further consists in the parts and combinations thereofhereinafter particularly set forth and claimed.

In order to makemy invention more clearly understood, I have shown inthe accompanying drawing means for carrying the same into effectwithout, however, limiting the improvement in its application to theparticular construction which, for the sake of illustration, I

' have delineated.

an electric railway, a lighting-circuit, powercircuit, or other electricconductor. G is the generator or source of electric energy for saidcircuit.

S is a safety device comprising a branch circuit a, connected with themain conductor A, and having therein a thermo-electricalinstrument,galvanometer, electromagnet, or other electro-mechanical device. In thedrawing the latter is shown as an electro-magnet at M, through the helixof which the circuit Cb passes. L is the armature-lever for said magnet,carrying or operating an electric contact P, adapted to engage or beseparated from a contact P. These contacts are in and form the means ofcompleting the circuit A. The branch circuit a is also provided withelectric contacts 1) p, which are adapted to be operated by a secondelectro-mechanical device, such as a magnet M and armature-lever L, thelatter carrying the contact 19 and the former having its helix in thecircuit A. The parts are arranged so that the attractive force of themagnet M will maintain a separation of the contacts pp. If now a breakoccur in the line A, such separation will cease, the circuit a will becompleted, and magnet M energized, and the circuit A will be positivelyand forcibly broken at PP by the operation of said magnet and its leverL. So much of the current from circuit A may be admitted to the circuita as is desirable, a suitable resistance or resistances being employed.

What I claim is In a safety device for electric circuits, thecombination, with the main circuit, of a branch circuit, anelectro-mechanical device therein, electric contacts in the main circuitadapted to be operated by said electro mechanical device, contacts inthe branch circuit, and an electro-mechanical device in the main circuitand adapted to control the latter contacts, substantially as set forth.

In testimony whereof I hereunto set my hand in the presence of twowitnesses.

MANDEVILLE THUM.

Witnesses:

H. N. Low, WILLIAM L. ALLEN.

